In 2008, while under economic sanctions and a U.N. travel ban, Bout was approached in Moscow by a close associate about supplying weapons on the black market to the Revolutionary Armed Forces of Colombia, or FARC.

Bout was told that the group wanted to use drug-trafficking proceeds to pay for surface-to-air missiles and other weapons, making it clear it wanted to attack helicopter pilots and other Americans in Colombia, prosecutors said.

Neither man knew at the time that the two FARC officials they were dealing with were undercover informants working for the DEA, said the associate, South African businessman Andrew Smulian, who took the witness stand for the government as part of a plea deal.

At first, Bout dismissed the idea of a deal, Smulian testified.

“He said he didn’t deal with drug dealers,” Smulian said.

Smulian testified that Bout overcame his doubts and agreed that for a down payment of $20 million he would arrange for cargo planes to air-drop 100 tons of weapons into Colombia. Bout finalized the phony deal with the two DEA informants in a bugged hotel room in Bangkok in March 2008.

The arrests came a day after Edelmiro Cavazos, 38, the mayor of Santiago, was buried. His body—gagged, blindfolded, and showing signs of torture—had been found on the side of the road after he was kidnapped.

“They have confessed,” Alejandro Garza y Garza, the attorney general of Nuevo Leon state, said at a news conference.

Six of the arrested police officers, including Mr. Cavazos’s bodyguard, were displayed to reporters. A seventh police officer was detained later Friday.

Mr. Garza y Garza said other arrests were imminent as well.

An eyewitness said a group of at least 15 gunmen, dressed in the uniforms of a defunct Mexican police force, drove up to Mr. Cavazos’ Santiago home in a convoy of SUVs.

Adrian de la Garza, head of the Nuevo Leon State Investigations Agency, said four of the arrested officers had guarded the highway while a group of kidnappers including one of the arrested officers grabbed Mr. Cavazos.

The mayor’s bodyguard, Jose Alberto Rodriguez, who was also arrested, was allegedly grabbed with Mr. Cavazos by the kidnappers, but released unharmed shortly afterward.

During the news conference, Mr. Rodriguez said he was innocent.

The alleged involvement of so many local police in the kidnapping and killing of Mr. Cavazos goes to the heart of Mexico’s security problem, analysts say.

Corruption is deeply entrenched among Mexico’s more than 2,000 municipal and state police forces, as well as in its relatively small federal police force.

Perhaps Felipe Calderon ought to work on that, instead of coming to the USA to criticize us.

About the only good news on this is that at least the policemen were arrested.

After the March 1 strike against a FARC compound in Ecuador, Colombia’s intelligence agencies immediately seized the pirate’s trove of information from the computers of terrorist Raul Reyes and put it to work.

They found that FARC was more than a local bunch of jungle-dwelling drug-runners. It turned out to be a 21st-century terror operation whose global operations reached deep into Mexico, Ecuador, Cuba, Russia, Eastern Europe and the Middle East.

In some nations, FARC controlled drug routes and raised money. In others, it bought weapons of war. In still others, it exported Marxist subversion. It also had bigger ambitions to forge ties with North Korea, Iran and China.

With $300 million in sponsorship from Venezuela, it also had a bright future. If it hadn’t been stopped dead by Colombia on the Ecuadorean frontier, it might have succeeded in all it was plotting.

FARC might have obtained enriched uranium, either to sell to other terrorists or to make a dirty bomb of its own. Computer correspondence shows that FARC offered millions for 50 kilograms of enriched uranium to one shady figure in Bogota.

Meanwhile, according to Colombia’s El Espectador, Reyes made a secret trip to Romania to scope out sellers. With uranium in hand, FARC could have taken out a city, possibly one in the U.S. In 2000, FARC sought a $100 million loan from Libya’s Muammar Qaddafi to purchase surface-to-air missiles.

Colombia’s swift use of intelligence also may have contributed to the fall of Victor Bout, a Russian weapons trafficker whose arms sales to savage regimes made him known as “The Lord of War.” He was not only a FARC quartermaster. He also supplied guns to Afghanistan’s Taliban, al-Qaida in Iraq and the monstrous warlords who scourged western Africa in the 1990s.

Five days after Reyes’ computer was confiscated, Bout somehow was lured out of his hiding place for a Drug Enforcement Administration sting. He now sits in a Bangkok jail.

American lawmen had access to information from Reyes’ computers, and it is likely something there persuaded Bout that it was safe to go to Bangkok. Taking him out of circulation will cut off arms to rogue actors in war-plagued regions such as Africa, as well as save American troops’ lives on overseas fronts.

Then there’s Mexico. In the March 1 raid, the Colombian army blew away five Mexican nationals whom some believe were taking a FARC explosives course.

Only about 5% of the data in the FARC computers has been explored by Colombian experts, and further revelations are likely. But what already has been mined shows how much Colombia has contributed to America’s security.

Police Col. Petcharat Sengchai told reporters that Bout was wanted for conspiring to provide “weapons and explosives for Colombian rebels” known as the Revolutionary Armed Forces of Colombia, or FARC. The leftist FARC has been fighting Colombia’s government for more than four decades, and funds itself largely through the cocaine trade and kidnapping for ransom.…He has been accused of trafficking weapons through a series of front companies to war-wracked Central and West Africa since the early 1990s. U.N. reports say he set up a network of more than 50 aircraft around the world, owned by small, tightly controlled companies including Bukavu Aviation Transport, Business Air Services and Great Lakes Business Co.